Pin locking mechanism for a surgical instrument

ABSTRACT

A surgical instrument comprising a handle portion, an elongated portion defining a longitudinal axis and extending distally from the handle portion, and first and second jaw members dimensioned to clamp tissue therebetween. The first jaw member has at least one row of fasteners arranged in a row substantially transverse to the longitudinal axis. A pin is disposed in mechanical cooperation with the first jaw member and is movable between a first position where the engagement section is spaced from the second jaw member and a second position where the engagement section engages the second jaw member. The pin has a non-circular cross-section.

This application claims priority from provisional application Ser. No.61/175,815, filed May 6, 2009, the entire contents of which areincorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates generally to a surgical instrument and,more specifically, to a surgical instrument for clamping, severing, andjoining tissue.

2. Background of Related Art

Certain surgical stapling instruments are used for applying rows ofstaples through compressed living tissue. These surgical staplinginstruments are employed, for example, for fastening tissue or organsprior to transection or resection or during anastomoses. In some cases,these surgical stapling instruments are utilized for occluding organs inthoracic and abdominal procedures.

Typically, such surgical stapling instruments include an anvil assembly,a cartridge assembly for supporting an array of surgical staples, anapproximation mechanism for approximating the cartridge and anvilassemblies, an alignment or guide pin assembly for capturing tissuebetween the cartridge and anvil assemblies and for maintaining alignmentbetween the cartridge and anvil assemblies during approximation andfiring, and a firing mechanism for ejecting the surgical staples fromthe cartridge assembly.

In use, the alignment pin assembly is advanced and the anvil andcartridge assemblies are approximated. Next, the surgeon tires theinstrument to place staples in tissue. Optionally, the surgeon may usethe same instrument or a separate device to cut the tissue adjacent orbetween the row(s) of staples. The alignment pin in some instances isadvanced automatically with approximation of the cartridge; in otherinstances it is advanced by a separate mechanism.

SUMMARY

The present disclosure provides a surgical instrument comprising ahandle portion, an elongated portion defining a longitudinal axis andextending distally from the handle portion, and an end effector disposedadjacent a distal portion of the elongated portion including a first jawmember and a second jaw member dimensioned to clamp tissue therebetween.

A pin is disposed in mechanical cooperation with the first jaw memberand includes an engagement section and is movable between a firstposition wherein the engagement section is spaced from the second jawmember and a second position wherein the engagement section engages thesecond jaw member. The pin has a non-circular cross-section.

Preferably, a knife is provided to move distally to cut the clampedtissue. Preferably, the knife has an upper edge terminating alongsidethe pin. In one embodiment, the pin has a gap dimensioned to accommodatethe knife. The instrument can include rows of fasteners with the knifepositioned between the rows.

In one embodiment, the pin is substantially semi-circular incross-section. In another embodiment the pin is substantially L-shapedin cross-section.

The instrument can include a second non-circular pin. In one embodiment,the pins are spaced from each other and one pin is adjacent a topportion of a knife and the other pin is positioned adjacent a bottomportion of the knife. The pins can be positioned on opposite sides of aknife slot from which the knife extends.

In some embodiments, the instrument can further include a second pinhaving a substantially semi-circular cross section, each of the pinshaving a substantially planar surface, the substantially planar surfaceof the second pin facing a direction opposite the direction thesubstantially planar surface the other pin faces.

The pins in some embodiments can move in a distal directionautomatically when the first and second jaw members move to a positionto clamp tissue.

In another aspect, a surgical instrument is provided comprising a handleportion, an elongated portion defining a longitudinal axis and extendingdistally from the handle portion, and an end effector disposed adjacenta distal portion of the elongated portion. The end effector included afirst jaw member and a second jaw member, the first and second jawmembers dimensioned to clamp tissue therebetween. The first jaw memberhas at least one row of fasteners arranged in a row substantiallytransverse to the longitudinal axis. A pin is disposed in mechanicalcooperation with the first jaw member and includes an engagementsection, the pin movable between a first position wherein the engagementsection is spaced from the second jaw member and a second positionwherein the engagement section engages the second jaw member. A secondpin is spaced from the first pin, the first pin and second pin eachhaving a surface alongside the knife wherein the first surface of thefirst pin faces in a first direction and the second surface of thesecond pin faces in a second opposite direction.

In some embodiments, the first and second surfaces of the pins aresubstantially planar. The first pin can have a third surface facingtoward a top surface of the knife and the second pin can have a fourthsurface facing towards the bottom surface of the knife. In someembodiments, the pins move in a distal direction automatically when thefirst and second jaw members move to a position to clamp tissue.

BRIEF DESCRIPTION OF DRAWINGS

Various embodiments of the presently disclosed surgical staplinginstrument are disclosed herein with reference to the drawings, wherein:

FIG. 1 is a perspective view of a surgical stapling instrument of thepresent disclosure;

FIG. 1A is a perspective view of an end effector of the instrument ofFIG. 1;

FIG. 1B is a side cross-sectional view of the end effector of theinstrument of FIG. 1 with the jaw members in the open position;

FIG. 1C is a side cross-sectional view of the end effector of FIG. 1with the jaw members in the closed position;

FIG. 2 is a close up perspective view of one embodiment of the cartridgeassembly having a pin with a semi-circular cross-section;

FIG. 3 is a perspective view of the area of detail designated in FIG. 2;

FIG. 4 a close up perspective view of another embodiment of thecartridge assembly having four rows of staples;

FIG. 5 is a close up perspective view of another embodiment of thecartridge assembly;

FIG. 6 is a close up perspective view of the area of detail designatedin FIG. 5; and

FIG. 7 is a close up perspective view of another embodiment of thecartridge assembly having two pins with a semi-circular cross-section.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Embodiments of the presently disclosed surgical stapling instrument aredescribed in detail with reference to the drawings, wherein likereference numerals designate corresponding elements in each of theseveral views. In the description that follows, the term “proximal”refers to the end or portion of the surgical stapling instrument closerto the user, whereas the term “distal” refers to the end or portion ofthe surgical stapling instrument further from the user.

In the interest of brevity, the present disclosure focuses on the pinfor a surgical stapling instrument designated in the drawings byreference numeral 100. U.S. Pat. No. 7,407,076, the entire contents ofwhich are incorporated by reference herein, describes in detail thestructure and operation of an embodiment of surgical stapling instrument100.

FIG. 1 illustrates a surgical stapling instrument 100 designed forapplying fasteners and cutting tissue. In brief, surgical staplinginstrument 100 includes a handle portion 110, an elongate portion 120,and an end effector 130 extending from the distal portion of theelongate portion 120. Handle portion 110 contains a trigger 140 foractuating end effector 130. Elongate portion 120 extends distally fromhandle portion 110 and defines a longitudinal axis A-A therealong. Endeffector 130 is disposed adjacent to a distal portion of elongateportion 120 and includes a first jaw member or cartridge assembly 150and a second jaw member or anvil assembly 160. In this embodiment,cartridge assembly 150 is adapted to move longitudinally with respect toanvil assembly 160 upon actuation of trigger 140 to clamp tissue betweenthe jaw members 150, 160. It is also contemplated that the anvilassembly can be moved (approximated) toward the cartridge assembly orthat the cartridge and anvil assemblies can both be moved toward eachother to clamp tissue.

Cartridge assembly 150 includes a plurality of slots 152 (FIGS. 1B and1C) each capable of holding a staple or any other suitable fastener.Each slot 152 is operatively associated with a pusher thrust bar orplunger 122. Pusher 122 extends along elongate portion 120 and partiallyinto cartridge assembly 150. Cartridge assembly 150 also includes aknife advanceable to cut tissue clamped between the cartridge and anvilassemblies 150, 160, respectively. In use, pusher 122 moves distallyupon actuation of trigger 140 and causes the ejection of the staplesdisposed in slots 152 in a distal direction, substantially parallel tothe longitudinal axis of the elongate portion 120. In addition to slots152, cartridge assembly 150 includes a pin 154 operatively connected topusher 122 and a bore 156 dimensioned to slidably receive pin 154. Pin154 is adapted to move longitudinally along bore 156 in response to atranslation of pusher 122. The pin 154 can alternatively be moved by asliding knob 155 in the handle portion 110. In the embodiment depictedin FIG. 1A-1C, anvil assembly 160 has a hole 162 designed to receive atleast a portion of pin 154. Anvil assembly 160 has staple-deformingpockets 164 for deforming the fasteners ejected from cartridge assembly150. An elongated slot can be provided between the pockets 164 in theanvil assembly to accommodate the knife described below.

While anvil assembly 160 remains stationary with respect to cartridgeassembly 150 during operation, cartridge assembly 150 is movablelongitudinally between a proximal position and a distal position uponactuation of trigger 140. In the proximal position, cartridge assembly150 is spaced apart from anvil assembly 160, as seen in FIG. 1B in anapproximated position. The actuation of trigger 140 causes clamp slides170, operatively connected thereto, to move distally which in turncauses thrust bar 122 to move distally due to pins 174. In turn, thedistal translation of thrust bar 122 causes the distal movement ofcartridge assembly 150 toward anvil assembly 160 to an approximatedposition. While cartridge assembly 150 moves from the proximal positiontoward the distal position, end effector 130 clamps any tissue placedbetween cartridge assembly 150 and anvil assembly 160 as shown in FIG.1C. In the distal position, cartridge assembly 150 is located closer toanvil assembly 160 and presses tissue “T” against anvil assembly 160.

Further actuation of trigger 140, i.e. a second squeeze of the trigger140, once cartridge assembly 150 reaches its distal (approximated)position causes ejection of the fasteners from slots 152. That is, thecontinued distal translation of pusher 122, once cartridge assembly 150is located in the distal position, causes the deployment of thefasteners positioned in slots 152. During deployment, these fastenersexit slots 152 and advance through tissue and into contact withstaple-deforming pockets 164 of anvil assembly 160 for formationthereof, e.g. bending of the staple legs into a “B” configuration.Actuation of trigger 140 also advances the knife to sever tissue clampedbetween the cartridge and anvil jaw assemblies 150, 160.

Note the distal motion of clamp slides 170 causes alignment pin 154 tomove distally along bore 156 due to the operative connection of thealignment pin pusher 172 to the clamp slides 170 via pins extendingthrough elongated slots in pin pusher 172 as described in U.S. Pat. No.7,407,076. (Pin pusher 172 includes a vertical portion having anabutment member configured to engage the proximal end of the pin 154.)Upon sufficient distal movement of pin 154, hole 162 of anvil assembly160 receives a portion of pin 154. The structural interaction betweenpin 154 and hole 162 (when cartridge assembly 150 is located in thedistal position) assists in the alignment of slots 152 withstaple-deforming pockets 164. It should be appreciated that alignmentpin 154 can alternatively be moved manually as pin pusher 172 is movedmanually, e.g. by sliding knob 155.

Turning now to embodiments of the alignment pins of the presentdisclosure illustrated in FIGS. 2-7, these pins can be used with thestapler of FIG. 1 described above or with other suitable surgicalstaplers. They can be configured to move automatically withapproximation of the cartridge, i.e. in response to actuation of thetrigger, and/or moved by the user separate from approximation, e.g. byan independent slidable knob or other manual controls or knobs locatedat various portions of the instrument. Thus, it should be understoodthat it is contemplated that the pins disclosed herein can be moved ineither way (automatic or manual) or in both ways.

FIGS. 2 and 3 illustrate a close up view of the cartridge assembly 150of FIG. 1. In this embodiment, cartridge assembly 150 includes aplurality of staple slots 132 and a knife slot 134. Each staple slot 132houses a staple or fastener 136. Knife slot 134 is adapted to receiveknife 138. Knife 138 is configured to move longitudinally to cut tissuebetween the staple rows. Preferably, knife 138 is advanced distally whenthe staples are advanced from cartridge assembly 150 through tissue. Inthis embodiment, two rows of staples are provided, extendingsubstantially linearly and substantially transverse to longitudinal axisA-A of the instrument 100. A different number of staples and staple rowsare also contemplated.

Cartridge assembly 150 further includes a bore 156 configured to receivea pin 154. Pin 154 is adapted to move longitudinally between a proximalposition and a distal position and has a substantially semi-circularcross-section to allow passage of knife 138 adjacent the pin 154. Thatis, the knife 138 passes by (alongside) the substantially planar innersurface region of the pin 154. The substantially semi-circular shape ofpin 154 allows the knife 138 to extend up to the region of the pin 154.As shown, the knife 134 extends past the bottom 154 a of the pin 154 andterminates adjacent an intermediate region 154 b of the pin 154. Otherknife heights are also contemplated. The staple slots 156 and stapleline extend beyond the top edge 138 a of the knife 138 and beyond thebottom edge 138 b of the knife 138.

FIG. 4 illustrates an alternate embodiment of the cartridge assembly,designated generally by reference numeral 250. Cartridge assembly issubstantially identical to cartridge assembly 150 of FIG. 2, except thatfour rows of staples are provided. As shown, the four substantiallylinear rows of staples 236 are arranged substantially transverse to thelongitudinal axis A-A of the instrument, with two staggered rowspositioned on either side of knife 238. As in the other embodimentsherein, the staples 236 are fired in a direction substantially parallelto the longitudinal axis of the instrument. The knife 238 is movablefrom knife slot 234 to sever tissue clamped between the cartridge andanvil assemblies. Pin 254 is substantially semi-circular shaped, similarto pin 154. The staples 236 extend beyond the upper and lower edges 238a, 238 b, respectively, of knife 238.

In the alternate embodiment of FIG. 5, cartridge assembly, designatedgenerally by reference numeral 350, is substantially identical tocartridge assembly 150 of FIG. 2, except for the configuration of pin354. As shown, two substantially linear rows of staples 236 are arrangedsubstantially transverse to the longitudinal axis of the instrument,with one row positioned on either side of knife 338. A different numberof rows are also contemplated. The knife 338 is movable from knife slot334 to sever tissue clamped between the cartridge and anvil assemblies.The staples 336 extend beyond the upper and lower edges 338 a, 338 b,respectively, of knife 338. Pin 354 is substantially L-shaped inconfiguration to create a gap 357 to accommodate the knife. That is,portion 354 a extends downwardly alongside the knife 338 and portion 354b extends transversely above the upper edge 338 a of knife 338.Consequently, the pin 354 extends in an arc of about 270 degrees(although other arcs are also contemplated).

It should be appreciated that although one alignment pin is shown, it isalso contemplated that two alignment pins can be provided, e.g. one onthe upper portion of the cartridge and the other on the lower portion ofthe cartridge. This is shown for example in the embodiment of FIG. 7,wherein upper pin 454 and lower pin 455 are provided in cartridge 450.Each of the pins 454, 455 are substantially semi-circular inconfiguration, similar to pin 254 of FIG. 2, however the substantiallyL-shaped pins of FIG. 5 could also be provided (either one at the top orbottom utilized with the substantially semi-circular pin on the opposingend or on both the top and bottom.) Note that the pins 454, 455 arepreferably on opposing sides of the knife 438. As in the otherembodiments, the staple line extends beyond the upper edge 438 a andlower edge 438 b of knife 438.

While the above description contains many specifics, these specificsshould not be construed as limitations on the scope of the presentdisclosure, but merely as illustrations of various embodiments thereof.Therefore, the above description should not be construed as limiting,but merely as exemplifications of various embodiments. Those skilled inthe art will envision other modifications within the scope and spirit ofthe claims appended hereto.

1. A surgical instrument, comprising: a handle portion; an elongatedportion defining a longitudinal axis and extending distally from thehandle portion; an end effector disposed adjacent a distal portion ofthe elongated portion, the end effector including a first jaw member anda second jaw member, the first and second jaw members dimensioned toclamp tissue therebetween, the first jaw member having at least one rowof fasteners arranged in a row substantially transverse to thelongitudinal axis; first and second pins disposed in mechanicalcooperation with the first jaw member, each pin including an engagementsection, the first and second pins movable between a first positionwherein the engagement section is spaced from the second jaw member anda second position wherein the engagement section engages the second jawmember, wherein each pin has a semi-circular cross-section, the firstand second pins spaced from each other; and a knife movable betweendistal and proximal portions, the knife having an upper edge terminatingalongside the first pin and a lower edge terminating alongside thesecond pin, a planar surface of the first pin located on a first side ofthe knife and a planar surface of the second pin located on a secondside of the knife that is opposite the first side such that the planarsurfaces of the pins are oriented towards each other.
 2. The surgicalinstrument of claim 1, further comprising two rows of fasteners, theknife positioned between the two rows of fasteners.
 3. The surgicalinstrument of claim 1, wherein the pins move in a distal directionautomatically when the first and second jaw members move to a positionto clamp tissues.
 4. The surgical instrument of claim 1, wherein eachpin is substantially D-shaped.
 5. The surgical instrument of claim 1,wherein the planar surface of the first pin is oriented towards thefirst side of the knife and the planar surface of the second pin isoriented towards the second side of the knife.
 6. The surgicalinstrument of claim 5, wherein the first side of the knife faces oneplanar surface of the first and second pins.
 7. The surgical instrumentof claim 1, wherein the planar surface of each pin is oriented towardsthe knife and a hemispherical portion of each pin extends away from theknife.
 8. The surgical instrument of claim 1, wherein the knife definesa longitudinal axis between the upper edge and the lower edge, each pinpositioned such that the planar surface of each pin does not extendacross the longitudinal axis.